Various methods have been considered to maintain continuity of the reproduced signal in conventional optical disc devices and spinning magnetic disc devices when information is recorded or read on the disc under vibrating conditions. In Patent Document 1, for example, additional memory is provided to store the reproduced signal, high-speed reading is performed, and the reproduced signal is temporarily stored in the memory, then read out sequentially, so even if control of the pick-up servo is lost due to vibration etc., continuous reproduction is possible even during the vibration by reading the information stored in the memory and retrying the control operation until the information in the memory is exhausted. In the method described in Patent Document 2, an additional acceleration sensor is provided to detect vibration, and the detected vibration information is added to the servo loop of the pick-up to cancel the effect of the external vibration on the pick-up.
Patent Document 1: Japanese Patent Application Publication No. 5-202565 (pp. 1-7, FIG. 1)
Patent Document 2: Japanese Patent Application Publication No. 9-27164 (pp. 1-5, FIG. 1)